Vacuum muffler



4 Sheets-Sheet l C. L. HILL VACUUM MUFFLER Filed Aug. s, 1940 Jun@ l0, @4L- June 10, 1941. C, L, HlLL, l 2,245,399

VACUUM MUFFLER Filed Aug. 3, 1940 4 Sheets-Sheet 2 June 10, 194L C; L. HILL 2,2455'599 VACUUM MUFFLER Filed Aug. 3, 1940 4 Sheets-Sheet 3 CHA/@455 /v/A/ L INVENTOR.

ATTORNEYS.

June 10, 1941., c. L.. HILL 2,245,399

VACUUM MUFFLER Filef"I Aug. 3, 1940 Sheets-Sheet 4 IN VENTOR.

ATTORNEYS.

Patented June 1G, lddl Charles L. Hill, Cranford, N. J.

Application August 3, 194.0, Serial No. 350,199

(Cl. ISI- 56) d Claims.

This invention relates to improvements in engine m-ulllers, and has particular' reference to a vacuum muflier of the type shown and described in U. S. Letters Patent No. 1,351,698, granted Charles L. Shuman and Soren Scott Hanson under date of August 3l, i920.

One of the important features of the invention resides in a vacuum muiiler especially adapted for heavy duty engines such as are used on heavy duty motor trucks, tractors, busses, marino motors, stationary engines and any other type of combustion power plant.

One of the important features of invention resides in a muffler which eliminates back pressure by u .lizing the velocity energy of the hot waste gases of combustion as they pass therethrough.

Another feature of the invention is to provide a vacuum muffler which functions to induce the free passage of waste gases of combustion therethrough, thus reducing. back pressure on an engine to an extent below atmospheric pressure, and preventinfr accumulation of gases within the muffler which may cause an explosion or backfire.

Other features are to provide a vacuum inui- Iier which is simple of construction so as to facilitate the easy taking of the same apart for cleaningr and reassembly, and which is strong and durable to withstand the pressure and heat to which the same may be subjected when in use.

Other features of the invention will become apparent as the following specification is read in conjunction with the accompanying drawings, in which:

Figure 1 is a iront elevational view of the Vacuum muffler.

Figure 2 is enlarged vertical transverse sectional view on the line 2N2 of Figure l.

Figure 3 is an inside face elevational View of the front casing section per se.

Figure 4 is an inside face elevation of the rear casing section with the intermediate baiile meinbers in position thereon and illustrating the iront face of the forward baffle member.

Figure 5 is a rear face elevational view of the forward baffle member per se.

Figure 6 is a view similar to Figure 4 with the forward baffle member removed and looking at the. iront face of the rear bathe member.

Figure 7 is a rear face elevational View of the rear member per se.

Figure 8 is an inside elevational view of the rear casing section.

Figure 9 is an enlarged detail vertical transverse sectional View on the line 9 5 of Figure 2.

Referring to the drawings by reference characters, the numeral lil designates my vacuum muffler in its entirety, which broadly includes a front casing section A, a rear casing section E, a forward intermediate baille member C and a rear intermediate baiie member D, all of which are formed of cast .durable metal capable of withstanding the heat and pressure of the heated waste gases of combustion to which they are subjected during use of the muiller.

The front casing section A is in the form of an annular shell and includes a side wall Il and an annular peripheral flange l2 having an annular groove i3 in the rear face thereof. Formed integral with the side wall Il and extending forwardly thereof and axially relative thereto is a collar lil having an inlet l5. The collar lf3 isV adapted to. be connected to the outlet end of an exhaust pipe leading from the exhaust manifold of an internal gas combustion engine. The side wall adjacent its periphery is provided with four equi-distantly spaced bolt openings I. Formed integral with and extending rearwardly of the side wall Il are equi-distantly spaced arcuate baffles Il which are helically directed toward the inlet l5, the adjacent baffles being in outwardly diverginrj relation. The ends of the lia-flies ll are curved and thereby gradually diminish. in width and they terminate short of the fiange l2 and inlet l5. Certain adjacent baffles il are connected approximately midway of their ends by webs i3, each of which has a notch or seat i9 to receive cooperating baflies provided on the front face of the baffle member C and which will be fully described hereinafter.

The rear casing section B is also in the form of an annular shell and includes a side wall 2) and an annular peripheral ilange 2i having an annular rib 22 on the free front face thereof which is complementary to and snugly lits into the groove I3. The open sides of the front and rear casing sections A and B are disposed in confronting relation and enclose the intermediate sections C and D in a manner to be hereinafter more fully explained. Formed integral with and extending rearwardly thereof and axially relative thereto is a collar 23 having an outlet 24. The inlet I5 and outlet 2li are in axial alinement as best illustrated in Figure 2 of the drawings. The side wall 2S adjacent its periphery is provided with four equidistantly spaced bolt openings 25, which are shown as square in cross section to receive the square portions at the head ends of fastening bolts 26. The openings 25 respectively aline with the openings I3 so that the bolts 23 may pass therethrough withthe threaded Shanks thereof extending beyond the casing section A and receiving clamping nuts 2'1. Formed integral with and extending forwardly from the side wall 29 are two spiral bailies '2S-23. Each baffle 29 extends from an edge of the outlet 24 and terminates adjacent but in spaced relation to the flange 2l, after making a complete convolution as best seen in Figure 8 of the drawings. The inner ends of the bailies 28-23 extend from diametrically opposite sides of the outlet 2li and their outer ends terminate at substantially diametrically opposite points. The spiral baffles 23-23 are so spaced that two helical passages 23-29 are provided whichgradually increase in width from their outer inlet ends which open into the outlet 24. The spiral bailles 28-28 are of a uniform width throughout their length except that they have their outer ends gradually reduced or inclined as at 39. The bafes 28-23 have equi-distantly spaced spacer lugs 3l extending from the free edges thereof for maintaining the baiile member D in spaced relation to the spiral baflies 28-28 of the casing section B.

The baiile member C comprises an annular plate 32 having a concentric opening 33 therein, the walls of the opening being iiared forwardly as at 34. The plate 32 is provided with a curved rearwardly extending ange 35 and extending inwardly from the flange are equi-distantly spaced arcuate baffles 33, the inner ends of which terminate short of the opening 33. Adjacent baiiies extend in outwardly diverging relation, thus the space therebetween is wider at the outer ends than at the inner ends. Three of the baffles 35 are arranged at one hundred and twenty degrees apart and are wider than the other bafiies for abutting engagement with the front sides of the baflle member D, for maintaining the members C and D in a fixed spaced relation. The periphery of the member C is notched as at 31 at four equi-distantly spaced points to receive the Shanks of the bolts 26.

.The front side of the baiile member C is provided with an annular series of arcuate baffles 38 which have their ends terminating short of the periphery thereof and short of the opening 33 as best seen by reference to Figure 4. Adjacent baiiles 38 are disposed in outwardly diverging relation so that the space between the bales is wider at the outer end than at the inner end. Three of the bafl'les arranged at one hundred and twenty degrees apart are wider than the others so as to abut the member A to maintain the member C in a iixed spaced relation relative thereto. The baffles 33 are staggered relative to the baiiies l1, so as to fit between each other in spaced overlapping relation and provide double the passages between the baiiles l1 and 38 to effect an initial separation and cooling of the gases after entering the inlet l5.

The baiile member D comprises an annular plate 39 having a forwardly extending concentric cone portion dii and a rearwardly extending axial hub portion il which terminates adjacent the walls of the outlet 2li to provide an annular restricted passage i! between the outlet chamber and the outlet. The periphery of the plate 39 is notched at four eoui-distantly spaced points as at i2 to receive the Shanks of the bolts 26. The front side of the plate 39 is provided with an annular series of arcuate bafes 153 which ter- 36 of the baille member C. The baflles 3 interfit between and are maintained in spaced relation with respect to the baiiies 33 with the apex of the cone portion 40 extending axially into the opening 33. The baffles 43 and 36 coact to double the number of passages between the members C and D and serve to initially break up and cool the heated gases which may enter through the opening 33.

The rear face of the plate 39 is provided with two spiral baiiles @i5-45 which are similar to and are complementary to the spiral bailles 28-28 of the member B. The inner ends of the baiiles 45-45 terminate at the hub il at diametrically opposite points while the outer ends thereof terminate in gradually decreasing width short of the periphery of the plate 39 (see Figure 7) The spiral baiiles 45 t into the spaces 29--29 of the bafl'le member'B and spiral bailles 28-28 overlap the spiral baiiles l5-45 as best seen in Figure 2. The lugs 3l on the baiiles 28 abut the rear face of the plate 39 of the baille member D to maintain the free edges of the baiiles 28 and 45 in a iixed spaced relation. The casing sections A and B, and baflie members C and D coact to provide two gas inlet chambers X and Y and a communicating outlet chamber Z, through which the hot gases must pass from the inlets l5 and 33 to the common outlet 2d.

In practice, assume that the collar I3 is connected to the outlet end of an exhaust pipe leading from the exhaust manifold of an internal combustion engine. The inlet I5 is of a greater diameter than the opening 33 in the forwardly flared portion of the baiile member C. The solid stream of gases entering the inlet I5 is broken up into a core stream which enters the inlet chamber Y through the opening 33 and an outer ring stream which enters the inlet chamber X between the baiile member C and front casing section A. Thus the volume of the gases entering the muliler is initially divided, a proportionate amount being lead to the chamber X, and a proportionate amount being lead to the chamber Y. The overlapping arcuate baiiles I'l and 38 and the overlapping arcuate baies 35 and 43 are disposed in the path of the laterally deected gases and these baffles act to cool the subdivided streams of gases as they flow toward the periphery of the members C and D. By reason of the arcuate shape of the baiiles |7-39, 33-93, the cooled gases are lead to the periphery of the members C and D in whirling streams, which cooled gases enter the outlet chamber Z deiined by the baflie member D and rear casing section B. This chamber Z is divided into four spiral communicating passages which have their inner ends meeting at the common outlet 24. The bailies l1, 38, 36, and 43, transfer their heat to the casing section Il, plate 32, and plate 39 respectively, and are thus cooled by conduction, for the casing sections and plate radiate the heat to the atmosphere. The initial cooling of the heat- Ved gases materially reduces the volume of the gases which enter the space between the spiral baflies 28 and 5 in a whirling state, and the cooled gases are maintained in whirling motion in a direction toward the annular restricted passage communicating with the outlet 24. As the initially cooled gases pass about the spiral baiiles 28 and 45, they are further subjected to cooling action and when reaching the outlet 24, the gases are exhausted to the atmosphere in a substantially noiseless stream. The whirling :action of the gases during their travel through the muiiier tends to induce the flow of the same, and prolongs the passage of the hot gases to assure cooling and avoids the accumulation of hot gases which are responsible for back pressure and back firing.

By reason of the novel construction of my improved vacuum muiiier, it is possible to quickly take the same apart for cleaning when the occasion demands. It is only necessary to remove the nuts 21 from the bolts 26, withdraw the bolts, whereupon the sections A, B, C and D, will readily become separated. The several sections may be cleaned of any accumulation of carbon and the parts readily reassembled.

Having thus described the invention, what I claim as new and desire to secure by Letters Patent of the United States, is:

1. A vacuum type muiiler comprising in combination, an annular casing having an axially alined inlet and an outlet in the respective opposed end walls thereof, a pair of baffle members, means for maintaining said baiile members in spaced parallel relation from each other and in spaced relation to the walls of said casing to provide a pair of gas inlet chambers and a single gas outlet chamber, the baille member nearest the inlet having a gas inlet opening in axial alinement with said inlet but of a smaller diameter, spaced overlapping arcuate shape baiiles on the confronting side walls of the inlet chambers to cause a whirling of the hot gases as they pass through the inlet chambers and for initially cooling the hot whirling gases, and spa-ced spiral overlapping -baies provided on the confronting side walls of the outlet chamber, the inner ends of the spiral baflies terminating at said outlet whereby the initially cooled gases are further cooled and whirled as they pass about the spiral baffles to be exhausted to the atmosphere through said outlet.

2. A vacuum type muler comprising in combination, a two part circular casing, one of said parts having a central gas inlet and a series of arcuate baffles o-n its inner surfaces, the other of said parts having a central outlet and a series of spiral baiiies on the inner side thereof surrounding said outlet, a pair of spaced plates, means for mounting said spa-ced plates in spaced relation to the walls of said casing, the plate nearest said inlet having a concentric inlet opening of smaller diameter than said inlet, the other of said plates having a stream diverting cone extending toward said inlet opening, spaced overlapping arcuate baffles provided on the confronting sides of said plates and being circularly arranged, a series of spaced arcuate baiiles provided on the other side of the plate having the inlet opening therein which are arranged in spaced overlapping relation with respect to the series of baiiles on the casing part, whereby to divide the volume of gases and impart an initial cooling of the gases entering the casing and for causing the incoming gases to be whirled toward the peripheries cf the plates, and a series of spiral baies provided on the other side of the plate having the diverting cone which are disposed in spaced overlapping relation to the spiral baiiies on the casing part for whirling the initially cooled gases to the outlet and for effecting a further cooling thereof.

3. A vacuum type muffler comprising in combination, an annular casing composed of two shell like casing sections, fastening bolts passing through said casing sections, a concentric inlet in o-ne end wall of said casing, an outlet in the opposed end wall of said casing in axial alinement with said inlet, a pair of annular plates having notches in their peripheries through which said bolts pass, the peripheries of said plates being disposed in spaced relation to the annular wall of said casing, means for maintaining said plates in spaced relation and in fixed spaced relation to the side Walls of said casing to divide the interior of the casing into a pair of gas inlet chambers and a single gas outlet chamber, the plate nearest the inlet having a gas inlet opening in axial alinement With said inlet but being of a smaller diameter, spaced overlapping arcuate baifles arranged in circular formation on the confronting side walls of the inlet chambers to cause a whirling of the hot gases as they pass through the inlet chambers and for initially cooling the same, and spaced spiral overlapping baiiles provided on the confronting walls of the outlet chamber, the inner ends of the spiral baiiies terminating at said outlet whereby the initially cooled gases are further cooled and whirled as they pass about the spiral bailies for subsequent exhaust to the atmosphere through said outlet.

4. A vacuum type muiiler as set forth in claim 3, in which that plate forming one side wall of the outlet chamber is provided on one side with a stream diverting cone which extends toward the inlet opening in the other plate, and a hub portion provided on the other side of said plate extending toward the `outlet and being of a smaller diameter than the outlet and concentric therewith and cooperating with the walls of the outlet to provide a restricted annular pasage between the outlet chamber and the out- CHARLES L. HILL. 

